Just cannabis? I've never had a psychedelic response, though large or strong hits can knock you on your ass for a few minutes. If you were hallucinating, then your tolerance is probably low (or, the edibles could be more potent than normal). I have friends that eat 1/4 to 1/2 a 5g gummy and that's good for them. My tolerance is high enough that I can eat 4-5 whole and not bat an eye. Some people also have built-in tolerances (or lack thereof), so it's best to start small and work your way up to a comfortable level.
Personally, I don't bother with edibles because they can be unpredictable and dwell in your system longer than you may want them to. If you do, get the fast-acting ones that kick in 15-30 minutes (made with live rosin), so you can gauge their effectiveness before taking more. They're good for plane flights and other public venues where you can't vape or smoke.